Precision casting equipment: analysis of the principle of low pressure casting

2021-3-29 20:38:29

The production process of precision casting equipment is diversified. Today, the editor will introduce the production process principle of low-pressure casting.

Low-pressure casting is a casting method in which liquid alloy is pressed into the mold cavity from bottom to top under pressure, and solidified under pressure to obtain castings. The principle of low-pressure casting is shown in Figure 1. The sealed crucible is filled with dry compressed air or inert gas, with the help of the pressure acting on the molten metal surface, the molten metal flows smoothly through the runner from bottom to top along the riser pipe The ground is filled with the mold, and the filling pressure is generally 20-60kPa. When the casting is completely solidified, the gas pressure on the liquid surface is released, so that the non-solidified molten metal in the riser pipe and the runner flows into the crucible by its own weight, then the mold is opened and the casting is taken out.

The production process of low pressure casting includes the following four basic procedures:

1) Metal smelting and preparation of molds or casting molds.

2) Preparation before pouring: including crucible sealing (fitting sealing cover), slag removal in riser pipe, measuring liquid level, sealing test, mold matching, tightening mold or casting mold, etc.

3) Pouring: including liquid lifting, filling, pressurization, solidification, pressure relief and cooling, etc.

4) Demoulding: including loose moulding and casting out.